Muscle
Triceps brachii
Chief elbow extensor
High-yield
Only extensor of the elbow; radial nerve. Triceps reflex tests C7. Long head separates quadrangular and triangular spaces.
Overview
The three-headed muscle of the posterior arm that is the main extensor of the elbow. Its long head crosses the shoulder.
Reference facts
- Origin
Long head: infraglenoid tubercle of scapula. Lateral head: posterior humerus above the radial groove. Medial head: posterior humerus below the radial groove
- Insertion
Olecranon process of the ulna
- Action
Extends the forearm at the elbow; long head extends and adducts the arm
- Innervation
Radial nerve (C6, C7, C8)
- Blood supply
Deep brachial (profunda brachii) artery